The present invention relates to a method of quickly and precisely monitoring the redox (oxidation-reduction) level of human blood plasma by the use of electron spin resonance (ESR) spectroscopy and to a method of estimating the progress of a dialysis according to the result of the monitoring.
Human blood plasma has homeostasis, i.e., has the ability or tendency to maintain internal equilibrium of biological functions by adjusting its physiological processes. However, where the plasma is taken out of the body, if a slight amount of oxygen is mixed into it, an oxidation reaction will progress. The details of the deterioration induced by oxidation reactions are understood only a little, due in part to the presence of anti-oxidants such as vitamins C and E. However, it is known that as oxidation reactions progress, the peroxide value of lipid in the plasma increases. It is said that the amount of peroxides is indicative of oxidation reactions. However, no report is made of the oxidation process that increases the peroxide value. It is reported that the peroxide amount in the body is varied by renal failure, which in turn varies the amount of active oxygen generated. However, no report is made of direct measurement of this variation.
It is quite important in the medical treatment of a kidney failure patient to determine if dialysis is immediately necessary or to determine the dialysis time if the dialysis is done. In the past, medical treatment was generally determined based on values obtained by various observations in judging the condition of a kidney failure patient. Hence, a quite high level of judgment technique has been required. Furthermore, any method of precisely judging the progress of a dialysis and precisely determining the end of the process has not heretofore existed. Therefore, prior art dialysis sessions have been routinely conducted for more than a sufficient time, whether the patient is in a serious or mild condition.
The present invention is intended to solve the foregoing problems, and provides a method of precisely judging the redox level of blood plasma in a short time using electron spin resonance (ESR) spectroscopy. This same method can also be used to estimate the progress of a dialysis in a short time by ESR. More particularly, the invention is a method of judging the redox of blood plasma by ESR spectroscopy such that active oxygen generated when the human blood plasma is placed in the presence of oxygen is trapped by a spin-trapping agent and that the amount of the generated spin adduct is measured by an ESR spectrometer. The progress of a dialysis is judged by electron spin resonance spectroscopy in accordance with the manner described below. First, blood plasma is taken from a dialysis patient. Active oxygen generated in the plasma under the presence of oxygen is trapped by a spin-trapping agent. The amount of the generated spin adduct is measured using an ESR spectrometer.